Conveyor mechanisms of the nonpowered type are basically rather simple in design and typically incorporate a conveyor frame structure defining a pair of spaced conveyor frame members having conveyor axle support receptacles formed therein. These axle support receptacles may conveniently take the form of elongated slots allowing drop-in type installation of conveyor rolls or, in the alternative, may take the form of noncircular apertures that enable the establishment of a nonrotatable relation between conveyor roll axles and the conveyor frame members. Typical conveyor roll structure includes a tubular conveyor roll element that may conveniently take the form of metal tubing having a bearing member received at each extremity thereof and establishing a friction tight or mechanically interconnected relationship therewith. The bearing structure typically incorporates inner and outer bearing races having bearing rollers or balls therebetween. The inner race of the bearing is formed to define a noncircular opening, typically of hexagonal configuration that is adapted to establish a nonrotatable interfitting relation with a conveyor axle extending therethrough. Typically, a conveyor axle is formed from a length of solid hexagonal stock and is typically received in slidable relation within the aperture of the inner bearing race. Obviously, in order to limit axial movement of the conveyor roll and bearing relative to the conveyor axle, a suitable retainer stop must be provided. In most cases, a simple stop pin is inserted through a transverse bore formed in the conveyor axle after the conveyor roll, bearing and axle have been installed in the conveyor frame. In some cases, axial movement of a conveyor axle is limited by providing an additional stop plate member at the outside of each conveyor frame, thereby closing the openings or slots within which the extremities of the axle are received. Providing additional stop plate members simply for the purpose of limiting axial movement of the various conveyor rolls is obviously an expensive procedure and detracts from the commercial feasibility of such conveyor mechanisms.
Typical conveyor roll assemblies, incorporating hexagonal axles are difficult to assemble and maintain in assembly during installation. As assembled, the hexagonal shaft or axle is free to move axially within the bearings at the extremities of the conveyor roll, and one must take great care to insure that one end of the axle does not move completely through the respective bearing and become disassembled from the inner race of the bearing. It is difficult and frequently requires considerable labor to rethread the hexagonal axle extremity through the mating opening of the inner race particularly when quite long conveyor rolls are being assembled and installed.
After a conveyor roll shaft and bearing assembly has been assembled, the assembly can be applied to a conveyor frame section in one of two ways. The first method of assembly is termed a "drop-in" application wherein the hexagonal axle shaft is merely dropped into two opposing axle slot receptacles that establish a nonrotatable relation between the axle and the conveyor frame, thus preventing the hexagonal conveyor axle from rotating during use.
The other type of application for conveyor roll assemblies of this nature is referred to as the "free-hole" type, wherein the conveyor side frames are punched or otherwise formed to define noncircular openings to receive mating noncircular axle ends of the various conveyor roll assemblies. Particularly, the conveyor frames are formed, typically by a punching operation, to define conveyor axle hole receptacles that are of hexagonal configuration so as to receive the hexagonal extremities of the conveyor axles thereof.
During installation, the extremities of the conveyor axles are threaded through the receptacle holes of the conveyor frames in order to install the conveyor roll assemblies. In order to accomplish assembly, the hexagonal shaft defining the axle must be pulled into the bearing on one end of the roller assembly; that end of the roller must be placed at a hexagonal hole and moved linearly sufficiently that the axle shaft comes within the bearing on the opposite extremity of the roll. This allows that extremity of the roll to be placed near the hexagonal hole receptacle of the other side frame member, after which the hexagonal shaft can be moved back through the conveyor roll in the opposite direction causing the opposite axle end to enter the hole receptacle of the frame.
After the conveyor roll assembly has been installed in this manner, it is necessary to provide suitable means for preventing the hexagonal axle shaft from moving linearly relative to the bearings and becoming inadvertently disassembled therefrom. One suitable means for limiting axial movement of the axle shaft relative to the conveyor roll is accomplished by locating a stop pin in the axle shaft, thus preventing the axle shaft from moving in either direction far enough to become disassembled from the axle receptacles of the conveyor frame. A considerable amount of labor and expense can be necessary for installation of conveyor systems of this nature, and it is therefore desirable to provide an improved conveyor system that effectively limits the amount of labor required during assembly.
As mentioned above, typical conveyor axles are formed from elongated hexagonal stock. This stock is typically solid bar stock, is quite heavy and expensive due to the amount of material required for the hexagonal stock. It is therefore desirable to provide an axle structure of light-weight and inexpensive construction without in any way sacrificing the standpoint of strength and function of the axle structure.
In view of the foregoing, it is a primary object of the present invention to provide a novel trapped-axle type conveyor frame and conveyor roll assembly incorporating an axle that is formed of light-weight and strong tubular construction and thereby reduces the amount of material necessary for forming the axle structure.
It is also a feature of the present invention to provide a novel trapped axle type conveyor frame and conveyor roll assembly wherein an axle structure is defined by tubular stock of cylindrical configuration, having the end portions thereof deformed by swedging or by other suitable means in order to define noncircular axle extremities adapted to be retained in nonrotatable relation within conveyor bearings and conveyor frame receptacles.
It is another novel feature of the present invention to provide a trapped-axle type conveyor frame and conveyor roll assembly wherein an axle structure is defined that forms intermediate stop surfaces functioning in conjunction with bearing elements to limit axial movement of the conveyor roll axle relative to the bearings and roll structure, thus trapping the conveyor axle without necessitating provision of additional stop elements as in the case of conventional conveyor roll assemblies.
It is another important feature of the present invention to provide a novel trapped axle type conveyor frame and conveyor roll assembly that may be readily and simply installed without requiring tedious threading of the conveyor axle structure within conveyor bearings in order to accomplish installation of the conveyor roll systems within conveyor side frames.
It is an even further feature of the present invention to provide a novel trapped-axle type conveyor frame and conveyor roll assembly that is of simple nature, is reliable in use and low in cost.
Other and further objects, advantages and features of this invention will become apparent to one skilled in the art upon an understanding of the illustrative embodiments about to be described, and various advantages, not referred to herein, will occur to one skilled in the art upon employment of the invention in practice.